Insulating material and process of making the same.



Uri TED STATES PATENT OFFICE.

JAMES C. PEABODY, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REPUBLIC MANU FACTURING COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS.

INSULATING'MATERIAL AND PROCESS OF MAKING THE SAME.

No Drawing.

To all whom it may concern Be it known that I, JAMEs G. PEABonY, citizen of the United States, residing at Boston, inthe county of Suffolk and State of Massachusetts. have invented a certain new and useful Improvement in Insulating Material and Processes of Making the Same, of which the following is a specification.

My invention consists in a new and improved material intended to take the placeof hard rubber and similar waterproof, non-heat conducting and electric insulating materials and which shall be suitable for the purposes for which these materials are now commonly employed, and which shall be capable of use under similar or analogous conditions.

The material embodying myinvention is capable of being shaped or molded under pressure and after being treated with heat becomes more or less waterproof, heatproof and acidproof, according to the length of time it is treated and to a certain extent to the proportions of the various substances employed in forming the material.

In the following specification, I have referred to the employment as one of the ingredients of a substance which I have termed a resin. By this term, I intend to include such substances as condensation products, of which phenol-resin is an example, also shellac. manila, and similar gums, also pitches and some mineral gums, the proper one being chosen with reference to the use to which the resulting material is to be put. The resin employed is in an uncombined state, that is, it is not in chemical combination with any other substance as is the case with resin soap.

The invention will be fully understood from the following description and the novel features will be pointed out in the claims at the close of the specification.

In the manufacture of my improved material I take paper pulp of any desired kind, such for instance as wood pulp and add to it While in the wet state a quantity of tlie resin'in the proportion of from three to eight ounces of the resin to each pound of dry pulp.

In practice, I powder or comminut-e the resin and make the powder into a paste with Specification of Letters Patent.

Patented Jan. 6. 1914.

Application filed October 6,1910. Serial No. 585.596. y

water. or some other suitable liquidzthere after I usually add to this paste sizing in the proportion of from about one-half to one ounce to each pound of the dry pulp. 'l he use of sizing is not believed to be absd lutely necessary but is thought to imprme the result with many kinds of resinsv The pulp is then put. into the ordinary beater well known to paper makers and water is added in the same proportion as if the pulp were to be used for the manufacture of paper. To the wet pulp is then added the paste composed as just described of the powdered resin and sizing. (if sizing be usedl. The mixture is then beaten in the beater in exactly the same manner as in the manufacture of paper. for a length of time depending upon the character of the paper pulp employed. Usually this is from three to eight hours. The effect of heating: is to incorporate the gum thoroughly with the fibers of the pulp and I believe that the sizingserves to convey the resin to the pulp and causes the same to adhere to the fibers thereof.

After the beatingprocess is completed,

the pulp may be formed into sheets either by means of cylinder machine or in a Fourdrinier machine being dried as it goes through the machine; or if desired it may be taken and placed in molds or forms and pressed and then dried either in the air or at a low heat. Thereafter, it is necessary to treatthe material with heatand pressure for the purpose of effecting a change in the material and rendering the material. hard, dense, waterproof and. while the heatand pressure is being applied it may be molded a second time to give it my desired form. During this part of the p'roc ess the temperature should be, I believe, preferably from 250 to 315 Fahrenheit. The pressure may be applied in any suitable manner as for instance by means of a hydraulic press; or if thin sheets are to be made, the heating step may be-performed by the use of hot cylinders. This molding and baking; under heat and. pressure should.

and dense like hard rubber. It is also capable of resisting heat under ordinary tem peratures and is Waterproof.

The degree of heat which it will resist, and thedensity and general resisting qualities of the material vary with the amount and character of the resin employed. For instance, if, a small amount of shellac is used, the material will be less resisting both to heat, acid and electricity, than if, phenol-resin be employed, and the resisting qualities will also be increased if the quality is increased.

The resulting product may be worked with machine tools, like hard rubber, and has a high tensile strength and will resist a heavy crushing strain.

While I have described in the foregoing specification the preferredmanner in which the process is practiced when a dry resin which has. been powdered is employed, it will be understood that a liquid form of the resin may be employed in which case it will be added directly to the pulp either wlth or without sizing. I

.What I claim is I 1. The process of making an insulating material which consists in adding free or uncombined resin to paper pulp, in the proportion of at least three ounces of the resin to a pound of dry stock, beating the mixture until the resin is distributed uniformly over the surface of the fibers composing the pulp,

' extracting the liquid and thereafter subjecting the material to heat and pressure.

2. The process of making an insulating material which consists in adding to paper pulp, in suspension in a liquid, a mixture of sizing and free or uncombined resin in'a proportion of at least three ounces of the resin to a pound of the dry fiber, beating the mixture until the resin is distributed uniformly over the surface of the fibers composing the pulp, extracting the liquid and thereafter subjecting the material to heat and pressure.

3. An insulating material which consists of paper fiber and free or uncombined. resin in a proportion of at least three ounces of 7 i the resinto a pound of the dry fiber, the resin being distributed uniformly over the surface of the fibers of the material, and the whole being densified and rendered homogeneous.

4. An insulating material which consists of paper fiber and free or uncombined resin in the proportion of at least three ounces of the resin to a pound of the dry fiber, and the resin being distributed uniformly over the surface of the fibers composing the mass. and the whole being densified' and rendered homogeneous by heat and pressure.

In testimony whereof I aflix my signature,- in presence of two witnesses.

JAMES C. PEABODY.

Witnesses GEORGE P. DIKE, ALICE H. Momuson. 

